New snow
- All elevations
As a consequence of new snow and wind a considerable avalanche danger will be encountered over a wide area.
The new snow and wind slabs are in some cases prone to triggering. Avalanches can be released by a single winter sport participant and reach large size in isolated cases. Backcountry touring calls for experience in the assessment of avalanche danger.
In particular on east, south and west facing slopes small and medium-sized moist avalanches are to be expected as a consequence of solar radiation.
Snowpack Fresh fallen snow and freshly generated snowdrift accumulations from the last few days are prone to triggering in some places. The snowdrift accumulations continue to expand in size and frequency, particularly on the northern Alpine Ridge from the Bernese Oberland into the Glarus Alps and in Grisons. Furthermore, in the upper sections of the snow cover there are in some places, expansively metamorphosed (faceted) and weakened layers evident, bordering against melt-freeze crusts. On west-facing, north-facing and east-facing slopes above approximately 2200 m more than anywhwere else, there are weak layers evident in the lower sections of the snow cover. In the western part of the Lower Valais and in the southern Valais, the deeply embedded weak layers inside the snow cover are blanketed over by only shallow layers of fresher snow and there, are prone to triggering in places. Observed weather review Thursday, 13.04.2023 Following a short interim in precipitation, snowfall set in once again from the west on Wednesday afternoon. During the nocturnal hours there was snowfall over widespread areas, during the daytime on Thursday there was snowfall particularly in the eastern regions. The snowfall level descended from 1800 m down to approximately 900 m. In the western and the southern regions there were occasional bright intervals. Fresh snow Between Wednesday afternoon and Thursday afternoon, the following amounts of fresh snow were registered:
Temperature At midday at 2000 m, between -6 °C in the northern regions and -3 °C in the southern regions. Wind
Weather forecast through Friday, 14.04.2023 On Thursday night, snowfall is anticipated over far-reaching areas above approximately 800 m except on the southern flank of the Alps; during the daytime hours on Friday, snowfall is expected in the eastern regions more than anywhere else. In the western regions, more extensive bright intervals are expected, in the Valais and in the Ticino it will be quite sunny. Fresh snow Between Thursday evening and Friday evening, the following amounts of fresh snow are anticipated above approximately 1500 m:
Temperature At midday at 2000 m, -4 °C in the northern regions, and -2 °C in the southern regions. Wind Winds will be blowing from northerly directions,
Outlook through Sunday, 16.04.2023 In the northern regions, frequent snowfall is anticipated above approximately 1200 m on both days. On the northern Alpine Ridge 30 to 50 cm of fresh snow is anticipated over widespread areas; as much as 60 cm of fresh snow is expected from the eastern Bernese Oberland into the Urner Alps. In the other regions of Switzerland, 10 to 30 cm over widespread areas is anticipated. In the southern regions it is expected to remain dry for the most part, and be quite sunny. Winds at heightened altitudes will be blowing at moderate strength from northwesterly directions, from northerly directions on Sunday in the southern regions. Avalanche danger levels are expected to increase over widespread areas, and increase particularly in the major areas of precipitation on the northern Alpine Ridge. There, during Saturday night, Danger Level 4 (high) can be reached. The conditions for winter sports in backcountry terrain away from secured ski runs are critical over far-reaching areas. The avalanche situation is somewhat more favourable on the southern flank of the Alps.
Bulletin data: WSL Institute for Snow and Avalanche Research SLF (CC BY 4.0)